This invention relates to mechanisms and articles adapted for lawn or turf aeration. More particularly, this invention is related to such mechanisms and articles incorporating tubular tines or coring tines for upward conveyance of columns of soil and thatch through turf surfaces, such tines leaving multiplicities of aerating channels within the turf surface.
Turf aerating tines are known to be configured tubularly, having a hollow dirt and thatch conveying bore, a beveled or chamfered thatch cutting distal end, and having a dirt and thatch outlet port extending through a side wall. Such tines are typically composed of durable steel, and typically have an outside diameter between xe2x85x9cxe2x80x3 and xc2xexe2x80x3. In use, such tubular tines are repeatedly and successively driven downwardly into and through a turf surface in need of aeration, and withdrawn upwardly from such surface. Upon each downstroke, such tine is driven downwardly through the turf surface, causing a column of undesirably thatched plant material or hard packed soil to enter the hollow bore of the tine. Upon each successive upward upstroke of such tine, soil and thatch encased within the tine is carried upwardly with the tine. Upon a next successive down stroke of the tine, a new column of soil and thatch is driven into the bore of the tine as the tine cuts through the turf, such action driving the overlying column of soil or thatch within the tine""s bore upwardly through the bore for emission from the tine""s outlet port. The emitted soil and thatch typically lays upon the surface of the lawn. The end result of repeated usage of such tubular tines upon a thatched or hard packed lawn is aeration, the lawn having a multiplicity of two inch to three inch vertically oriented hollow aerating shafts. The multiplicity of aerating shafts beneficially promotes moisture penetration, stimulating root growth and hastening thatch decomposition. Tubular or coring tines, when used in the above described manner, aerate lawns more efficiently than solid tine aerators, requiring less down force upon the tines in order to cut an acceptably large aerating channel through the turf surface.
A known means for repeatedly downwardly driving and upwardly withdrawing tubular tines into and out of a lawn surface is to rotatably mount radial arrays of such tines upon an axle, and to press the arrays of tines downwardly upon a lawn surface while rolling the tine arrays horizontally over the surface. The necessary successive tine downstrokes and upstrokes is provided by their orbital movement about the axle""s axis of rotation. Such known assemblies commonly undesirably over-insert the tines where the turf is soft, and under-insert the tines where the turf is hard and compacted. Such assemblies also tend to undesirably gouge and tear turf surfaces.
The instant inventive turf aerator solves or ameliorates the above described undesirable traits of rotary mounted tubular tined aerators by mounting radial arrays of tubular aerating tines upon side walls of lawn rollers, allowing the rollers to simultaneously function as a lawn smoothing and leveling means, as a tine driving means, as a tine insertion depth control means, and as means for minimizing turf gouging and tearing during aeration. The inventive side wall mount of the tubular tines allows the roller element to perform its normal smoothing and leveling function while preventing the roller""s annular surface from interfering with upward conveyance of dirt and thatch through the bores of the tubular tines.
A first structural component of the instant inventive turf aerator comprises at least a first roller. Preferably, the roller comprises a substantially solid cylindrical body formed of a molded concretion such as Portland Cement. A drum or cylinder mold is preferably utilized for casting the preferred cylindrical body concrete roller, such mold having a cylindrical shaft such as a dowel or pipe extending axially therethrough. Preferably, the outside diameter of the dowel or pipe is closely fitted to the outside diameter of a lawn working implement axle upon which the roller is to be rotatably mounted. Preferably, such mold further has a smaller diameter pin or shaft, ideally a threaded bolt, extending transversely therethrough, the pin or bolt passing perpendicularly through the axially extending pipe or dowel. Also preferably, a plurality of spirally threaded bolts are supported upon the side walls of the drum mold so that their threaded ends extend laterally outward from the drum mold in parallel alignment with the axis of rotation. Also preferably, the end walls of the drum mold are configured for casting inset semi-circular tine receiving channels within the end walls of the concrete roller. The inside diameters of the semi-circular channels are preferably fitted for nesting receipt of coring or tubular tines. The laterally extending bolts are preferably positioned in relation to the semi-circular channels so that such bolts extend laterally outwardly from the floors of such channels. The exposed ends of such bolts serve as threaded tine mounting lugs, while the embedded heads and shafts of such bolts preferably dually serve as concrete reinforcement bars and mounting lug anchors. Upon filling of such mold with wet concrete and upon drying and setting, the transversely extending pin, the axially extending dowel, and the mold shell are withdrawn in succession, leaving a final cylindrical body having laterally extending lugs for tine mounting, having an axially extending axle receiving channel, and having a transversely extending drive pin receiving channel. The laterally extending threaded lugs in combination with the tine receiving channels effectively comprise a preferred tine mounting means for connecting radial arrays of tubular tines to the side walls of the roller.
Ideally, the threaded bolt used to form the transverse channel has a spirally threaded hexagonal or square nut threadedly mounted upon its inner end so that, upon threaded extraction of such bolt from the newly molded concrete roller, the pin receiving channel includes at its inner end the threaded nut, facilitating secure bolt mounting and alternate disassembly.
A second component of the instant inventive turf aerator comprises at least a first tubular tine, and preferably laterally paired arrays of tubular tines, mounted upon the side walls of the roller. Necessarily, the at least first tubular tine has an outer end and an inner end, the outer end being displaced radially from the axis of rotation of the roller a distance greater than the radial displacement of the annular surface of the roller, and the inner end of such tine being displaced radially a distance less than that of such annular surface. Such arrangement of the tubular tines allows an outer portion of each tine to extend radially outward for turf insertion, allows an inner portion of each tine to extend radially inward for secure tine mounting, and provides for free passage and conveyance of soil and thatch through the bore of each tine without blockage or clogging caused by the roller""s annular surface. The above described molded concrete cylindrical body roller advantageously additionally performs a ballast or weighting function, assisting in downwardly driving the tubular tines through turf surfaces.
While the above described molded concrete cylindrical body represents a preferred roller for use as a component of the instant invention, other roller types may be suitably utilized. For example, a metal cylinder comprising rolled sheet metal or a pipe segment may serve as the roller element. Where a metal cylinder substitutes for the preferred concrete cylinder, the metal cylinder may be adapted to include additional ballast or weight by capping the lateral ends of the cylinder, forming a closed drum, and by filling the cylinder with a heavy material such as sand or lead. Alternately, a substantially solid metal cylindrical body having no hollow ballast receiving space may serve as the roller element. Also alternately and suitably, a hollow plastic cylinder or plastic cylindrical body may be utilized as the roller element. Also alternately and suitably, the roller element may comprise a wood cylinder or wood cylindrical body. Also alternately and suitably, a composite laminate cylinder or cylindrical body may be utilized.
While the above described semi-circular channel and threaded mounting lug tine mounting means is preferred, numerous other tine mounting means may be suitably utilized. For example, the tines may be mounted upon roller side walls by threaded bolts extending through the tines and into and through the side wall of the roller to threadedly engage a spirally threaded side wall aperture or an embedded spirally threaded nut. As further examples, spirally threaded screws, nails, slip pin and pressure ring combinations, slip pin and shear pin combinations, interlocking ridge and channel combinations, interlocking pin and sleeve combinations, hook and eye combinations, quick disconnect couplings, adhesives, pressure fitted joints, rivets, blind fasteners, heat fusion welds, homogenous joints, or whole formed joints may be suitably utilized as means for mounting the tubular tines upon the side walls of the roller.
While the above described axially extending axle receiving channel comprises a preferred means for rotatably mounting the roller, other rotating means may be suitably utilized. For example, axle receiving sleeves may be axially mounted within the roller along the roller""s axis of rotation. As a further example, axle receiving bearing rings may be similarly axially mounted. Also, end walls of the roller may suitably be configured to include axially extending journals. Also suitably, a fixed axle mount may be bolted or welded to a side wall of the roller.
In a preferred embodiment of the instant invention, a pair of tined rollers, each preferably configured in accordance with the preferred embodiment described above, are mounted upon laterally extending drive axles of a common walk-behind rototiller, whose tilling tines have been removed. Where the inventive tined rollers are utilized in conjunction with such common rototiller, the rollers are particularly advantageously configured to include internal ballast or weight, such as concrete, sand fill, or lead fill. Many walk-behind rototillers are light weight and have no convenient space for mounting and carrying separate weights or ballast. Locating weight or ballast within the roller of the instant inventive turf aerator allows usage upon light weight rototillers. Alternately, a plurality of the instant inventive turf aerators may be rotatably mounted upon a frame adapted for trailering behind a tractor. Where such trailered configuration is utilized, the frame which rotatably supports the rollers may suitably be configured for mounting and carrying of additional ballast or weight, lessening the need for situating ballast or weight within the rollers. Also alternately, the frame upon which the inventive turf aerators are mounted may be configured as an auxiliary implement attachable to the boom arm or lift arms of mobile construction equipment such as tractor backhoes, excavators, and skid steer loaders. Where the inventive turf aerators are rotatably mounted upon such auxiliary implements, acceptable down force may be provided via the lift arms or boom arm without the provision of additional weight or ballast. The above described rototiller, boom arm auxilliary implements, lift arm auxilliary implements and trailering implements comprise suitable means for rotatably supporting the plurality of inventive turf tillers in axial alignment.
Accordingly, it is an object of the present invention to provide a turf aerator which incorporates a roller with a tubular tine for simultaneously performing turf smoothing and leveling, tine depth control, weighted tine driving, and turf gouge and tearing reduction.
It is a further object of the present invention to provide such a turf aerator which positions its tines with respect to its roller to allow free passage of dirt and thatch through the bores of the tines without blockage or interference by the annular surface of the roller.
Other and further objects, benefits, and advantages of the present invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings.